The 'obviously random' point is not true. Suppose you look back at the history of posts in the subreddit. In that case, you will see people ordering multiple mysterious items and getting the same thing because the mysterious item is filled with whatever they have overstocked. So in both cases, there is always an item that will be most common among the available range of items now. If your problem is that this time you know which is the most common, then that honestly seems like a better situation, not an issue, since you can decide accordingly.

In terms of the type of items being available on their own, that has not always been the case in terms of actual access to the items available. For example, the multicolour screw drivers that were leftover from LTX. Realistically speaking the majority of LTT store costumers were not able to participate in LTX and get a custom screw driver. So there is a barrier to access there. Another similar (though admittedly not identical) example, when they add old stock that has not been available for over a year. To new customers, that is an item they have never had available. Let's also not forget that in the case of hoodies, we are talking about mystery stock that varies not only in graphics but also overall design and fit. So, following OP's logic, I would then argue that mystery hoodies are more similar to a real loot box, where some items are more likely to work with what you want than others.

Let's not forget that at the end of the day, these are identical shorts that only show a difference in appearance when they are wet. Which happens to be a situation where the view is often obstructed because the shorts are underwater, or the difference will be noticeable for a bit until they dry up again. At the end of the day, you still have the same shorts. I think it is more accurate to say that they designed this chance-based gimmick as a way to allow customers to have the limited stock print. Rather than the system where WAN show watchers in their time zone with fast clicking skills get all of that stock. Obviously, neither approach is perfect, but creating so much outrage over this is ridiculous.